‘I don’t think I’m big enough for the Presidency,’ Warren G Harding complained after his inauguration as President of the United States in 1921: ‘I can’t make a damn thing out of this tax problem. I listen to one side and they seem right, and then – God! – I talk to the other side and they seem just as right … Somewhere there must be a book that tells all about it. My God! But this is a hell of a place for a man like me to be in.’